It is a virtuous cycle if there ever was one: when students enjoy reading, they tend to read better, which makes reading easier and more enjoyable, so they read more, and so on. Better readers not only perform well in school, they grow up to become adults who use their reading skills to make sense of the world around them and continue learning throughout their lives.

But for many students around the world, that cycle appears to have broken. Even though better reading performance in PISA is more associated with reading for pleasure every day than with how many hours a student spends reading, the latest issue of PISA in Focusreports that, in 2009, only around two-thirds of students in OECD countries said that they read for pleasure daily; and in most OECD countries, the proportion of students who said they read for enjoyment was smaller in 2009 than it was in 2000.

Reading for pleasure is also associated with girls – there’s a 20 percentage-point gender gap among 15-year-olds who read for enjoyment – and with socio-economic advantage – on average across OECD countries, 72% of advantaged students read for pleasure while only 56% of disadvantaged students do. And in as many as ten OECD countries, that latter gap is more than 20 percentage points wide.

It’s troubling enough that in 2009 fewer boys and girls reported that they read for pleasure than their counterparts did in 2000; but PISA results also show that the decline is steeper among boys in nearly all countries.

There’s much more at stake, here, than performance on PISA reading tests. To have the habit of reading, which is much easier to develop when one actually enjoys reading, is to have the key to the store of knowledge acquired through the millennia, the tools to interpret and apply that knowledge, and the foundation on which to build a lifetime of learning. Parents and educators can instil and feed this invaluable habit by having books available at home, reading to and in front of their children, and suggesting reading material that students find interesting and relevant. The late American psychologist B. F. Skinner had a point: “We shouldn’t teach great books; we should teach a love of reading.”